This investigation proposes to study various groups of U.S. and Mexico inhalant users in a series of joint and related studies focusing on young adults. We aim to: 1) Complete an ethnographic study of inhalant use consisting of (a) and analysis of individual users, (b) an analysis of the social context; (c) an analysis of the institutional framework which interfaces with inhalant users. 2) Evaluate the relationship of inhalant use and aggressive behavior; investigate aggressive responses in relationship to such variables as degree of frustration, range of coping strategies available, degree of impulsivity. Examine a number of personality variables to assess underlying psychological mechanisms. 3) Investigate the relationship of the development of tolerance for inhalants to patterns of inhalant use. 4) Describe the extent of psychological dependence upon, and committment to inhalant use. Relate to sex and ethnic differences. 5) Quantify the extent of physical dependence upon inhalants and relate to patterns of use; chart clinical picture of withdrawal. 6) Evaluate biomedical and neuropsychological status of heavy inhalant users in comparison to other drug users.